c# - 如何对数据表中的列求和？

Question

如何获取数据表中所有列的总和？假设我有下表。如何计算“总计”行？将总行添加到数据表应该很容易。

         Columns    hits     uniques    sigups, etc...
Rows                  
1                      12         1         23
2                       1         0          5
3                       6         2          9


total                  19          3        37

更新

我结束了这个。这是我唯一可以开始工作的东西。

 For Each col As DataColumn In TotalsTable.Columns    
    If col.DataType.Name = "DateTime" Then
            count = count + 1
                Continue For
        End If

        Dim colTotal As Double = 0
        Dim value As Double

        For Each row As DataRow In TotalsTable.Rows
            If Double.TryParse(row(col), value) Then
                    colTotal += Double.Parse(row(col))
                    End If
        Next

    totalRow(count) = colTotal
        count = count + 1

  Next

Answer 1

还有一种不用循环的方法，使用 DataTable.Compute Method .以下示例来自该页面。你可以看到使用的代码非常简单。:

private void ComputeBySalesSalesID(DataSet dataSet)
{
    // Presumes a DataTable named "Orders" that has a column named "Total."
    DataTable table;
    table = dataSet.Tables["Orders"];

    // Declare an object variable. 
    object sumObject;
    sumObject = table.Compute("Sum(Total)", "EmpID = 5");
}

我必须补充一点，如果你不需要过滤结果，你总是可以传递一个空字符串:

sumObject = table.Compute("Sum(Total)", "")